Abdominal exercise devices have recently gained popularity with the American public. Consumers are flooded with advertising which promise of a midsection with a six-pack yet allowing you to continue to drink as many six-packs as you desire. Though many are inaccurate, the value of strengthened abdominal muscles is well documented in the scientific literature. These core muscles including the rectus abdominis and the internal and external obliques support proper posture and support lower back health. For those with low bodyfat, the sections of the rectus abdominis show through the skin, revealing that prized “six-pack”. A true abdominal exercise device must enable a contraction of the main abdominal muscle, the rectus abdominis. This muscle is located on the anterior portion of the abdomen. The action of this muscle is to move the chest toward the groin in such a way as to cause the spine to flex forward. If the chest moves toward the knees with the back straight, the primary movers are the hip flexors (including the psoas muscle). In this case the rectus abdominis contracts only to stabilize the spine to prevent it from bending backward. Any resistive movement of the chest, while it moves forward, thereby curing the spine, results in abdominal muscle stimulation.